trouble getting paid with new job in USA

I need to get some advice.. it is for my girlfriend who is working as a Physiotherapist in New Jersey. I have been helping her as she has been overwhelmed with everything. I am in Canada and she was living here but is now in New Jersey working on a working visa.
Her first job, a man who sponsored her (she is from the Philippines) did not pay her properly and did not treat her well. I am not naming any names yet with respect to her and her integrity, but she has really been abused and we are not sure what steps Americans take without going to the courts.

The worst abuse is she has not been paid accordingly: she arrived there in June.. worked for this guy in New Jersey, for over one week of training and then about 5 weeks of work as a licensed physiotherapist. The verbal agreement was $30/hour. She has been naive in not getting anything in writing. It was not clear about this training pay- about 40 hours. He paid her only $300 for this. Then she started working after leaving and returning..long story.. but her sister is in another state so she stayed there while awaiting her license and getting a driver's license.

Now that she got certified, she worked for him for around 5 weeks, from early July mid. August, and he gave her only $500 cash and then bounced the cheque. He has been very evasive for her.. she has waited upon him as he said to meet her for her pay and does not show up, and other games he plays on her. He had some woman talk to her, also a Philippino, who basically threatened her that she could go to jail if she quit while being sponsored by him. My girlfriend actually never worked for him but for his friend who has a clinic and but he (the original employer) was to pay her for this work. The original employer has a Chiropractor office (had 5 of them, but 4 went bankrupt and has only one now). She had to work for his friend who was mean to her, so she quit.
Now she has a better job and has to move again. She has had to return to Canada to renew her visa and needless to say she is badly in debt. It seems so wrong to me as a Canadian teacher, that people in a professional body can get away with this, so I am helping her get help. I know help should be there somewhere, without her spending money she does not have. She is not part of any Physiotherapy board, but I am wondering what someone there would advise. She is looking into the Labour relations board to get the paper work and to put in a complaint, but is there some way to pressure this guy to pay while maintaining her professionalism? I will add that she is a very kind, tiny, and beautiful woman, so I fear for her safety down there but know there are kind people everywhere. It is just a little risky while she is there alone and trying to do all this on her own.

so I will appreciate any advice.
I will pass any advice onto her.
thanks